Pet door



FIG. 1 is a front, right side, top perspective view of a pet door showing my new design;

FIG. 2 is a rear, right side, top perspective view thereof;

FIG. 3 is a front elevational view thereof;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof;

FIG. 7 is a top plan view thereof;

FIG. 8 is a bottom plan view thereof;

FIG. 9 is a cross-sectional view of the pet door taken along line 9-9 in FIG. 3 ; and,

FIG. 10 is a front, right side, top perspective view of the pet door, shown in an open position of use.

The broken lines depict portions of the pet door that form no part of the claimed design. 

CLAIM The ornamental design for a pet door, as shown and described. 